Current difference sensors, systems and methods

Patent metadata

Field	Value
Publication number	US-9678172-B2
Application number	US-201514636573-A
Country	US
Kind code	B2
Filing date	Mar 3, 2015
Priority date	Jan 24, 2011
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

Embodiments relate to current difference sensors, systems and methods. In an embodiment, a current difference sensor includes first and second conductors arranged relative to one another such that when a first current flows through the first conductor and a second current, equal to the first current, flows through the second conductor, a first magnetic field induced in the first conductor and a second magnetic field induced in the second conductor cancel each other at a first position and a second position; and first and second magnetic field sensing elements arranged at the first and second positions, respectively.

First claim

The invention claimed is:

1. A current difference sensor comprising:
a first conductor configured to conduct a first current that generates a first magnetic field component in a first direction;
a second, different conductor configured to conduct a second current that generates a second magnetic field component in the first direction;
a first magnetic field sensing element, arranged at a first position, configured to sense the first magnetic field component and the second magnetic field component in the first direction;
a second magnetic field sensing element, arranged at a second position, configured to sense the first magnetic field component and the second magnetic field component in the first direction;
wherein the first conductor and the second, different conductor, located proximate to one another, are configured to approximately cancel the first magnetic field component in the first direction and the second magnetic field component in the first direction in response to the first current flowing through the first conductor and the second current flowing through the second conductor.

2. The current difference sensor of claim 1 , wherein the first conductor and the second, different conductor are configured to approximately cancel the first magnetic field component in the first direction and the second magnetic field component in the first direction, at a first location and at a second location, in response to the first current flowing through the first conductor and the second current flowing through the second, different conductor.

3. The current different sensor of claim 1 , wherein a sum of the first magnetic field and the second magnetic field at a first location is approximately equal to a sum of the first magnetic field and the second magnetic field at a second location.

4. The current difference sensor of claim 1 , wherein the first current is approximately equal to the second current.

5. The current difference sensor of claim 1 , further comprising circuitry, coupled to the first magnetic field sensing element and the second magnetic field sensing element, configured to determine a difference between magnetic fields being sensed at a first location and a second location.

6. The current difference sensor of claim 1 , further comprising circuitry, coupled to the first magnetic field sensing element and the second magnetic field sensing element, configured to determine a difference between the first current and the second current based on magnetic fields at a first location and at a second location.

7. The current difference sensor of claim 1 , further comprising a plurality of magnetic field sensing elements, the first magnetic field sensing element and the second magnetic field sensing element being two of the plurality of magnetic field sensing elements, wherein the first magnetic field sensing element and second magnetic field sensing element from the plurality of magnetic field sensing element comprise a lower sensitivity to a sum of the first current and the second current and a higher sensitivity to a difference between the first current and the second current with respect to other magnetic field sensing elements of the plurality of magnetic field sensing elements.

8. The current difference sensor of claim 1 , further comprising a plurality of magnetic field sensing elements, the first magnetic field sensing element and the second magnetic field sensing element being two of the plurality of magnetic field sensing elements, the plurality of magnetic field sensing elements arranged in a grid pattern with respect to one another across a first surface of a die.

9. The current difference sensor of claim 8 , wherein the die is arranged at a tilt angle with respect to a center of symmetry between the first conductor and the second conductor.

10. The current difference sensor of claim 8 , wherein the die comprises a second surface that is opposite to the first surface, and wherein the second surface is positioned closer to the first conductor and the second conductor than the first surface.

11. The current difference sensor of claim 1 , wherein the first conductor and the second, different conductor are asymmetrical in shape with respect to one another.

12. The current difference sensor of claim 1 , where the first magnetic field sensing element is an anisotropic magnetic field sensing element or a giant magnetic field sensing element, and where the second magnetic field sensing element is an anisotropic magnetic field sensing element or a giant magnetic field sensing element.

Assignees

• Infineon Technologies Ag

Inventors

• Ausserlechner Udo
• Astegher Berthold

Classifications

• G01R15/202

  using Hall-effect devices (Hall elements in arrangements for measuring electrical power G01R21/08) · CPC title

• G01R33/06 Primary

  using galvano-magnetic devices · CPC title

• G01R17/02 Primary

  Arrangements in which the value to be measured is automatically compared with a reference value · CPC title

• G01R33/096

  anisotropic magnetoresistance sensors · CPC title

• G01R15/20

  using galvano-magnetic devices, e.g. Hall-effect devices {, i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices} · CPC title